CVE-2026-33747: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in moby buildkit
CVE-2026-33747 is a high-severity path traversal vulnerability in moby buildkit versions prior to 0.28.1. It allows a malicious custom BuildKit frontend, specified via `#syntax` or `--build-arg BUILDKIT_SYNTAX`, to write files outside the intended BuildKit state directory by sending a crafted API message. Well-known frontend images such as `docker/dockerfile` are not affected. The issue has been fixed in version 0.28.1.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-33747) in moby buildkit is a CWE-22 path traversal flaw affecting versions before 0.28.1. A malicious custom BuildKit frontend can exploit this by sending a specially crafted API message, enabling it to write files outside the designated BuildKit state directory. This could lead to unauthorized file writes impacting confidentiality, integrity, and availability. Officially recognized frontend images like `docker/dockerfile` are not vulnerable. The flaw has been resolved in buildkit version 0.28.1.
Potential Impact
Successful exploitation allows an attacker controlling a custom BuildKit frontend to write files outside the intended directory, potentially leading to arbitrary file creation or modification. This compromises confidentiality, integrity, and availability of the system where buildkit runs. However, well-known frontend images are not affected, limiting exposure to custom or untrusted frontends.
Mitigation Recommendations
Upgrade moby buildkit to version 0.28.1 or later, where this vulnerability is fixed. Avoid using untrusted custom BuildKit frontends as a temporary measure. Patch status is confirmed fixed in 0.28.1.
CVE-2026-33747: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in moby buildkit
Description
CVE-2026-33747 is a high-severity path traversal vulnerability in moby buildkit versions prior to 0.28.1. It allows a malicious custom BuildKit frontend, specified via `#syntax` or `--build-arg BUILDKIT_SYNTAX`, to write files outside the intended BuildKit state directory by sending a crafted API message. Well-known frontend images such as `docker/dockerfile` are not affected. The issue has been fixed in version 0.28.1.
CVSS v3.1
Score 8.4high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-33747) in moby buildkit is a CWE-22 path traversal flaw affecting versions before 0.28.1. A malicious custom BuildKit frontend can exploit this by sending a specially crafted API message, enabling it to write files outside the designated BuildKit state directory. This could lead to unauthorized file writes impacting confidentiality, integrity, and availability. Officially recognized frontend images like `docker/dockerfile` are not vulnerable. The flaw has been resolved in buildkit version 0.28.1.
Potential Impact
Successful exploitation allows an attacker controlling a custom BuildKit frontend to write files outside the intended directory, potentially leading to arbitrary file creation or modification. This compromises confidentiality, integrity, and availability of the system where buildkit runs. However, well-known frontend images are not affected, limiting exposure to custom or untrusted frontends.
Mitigation Recommendations
Upgrade moby buildkit to version 0.28.1 or later, where this vulnerability is fixed. Avoid using untrusted custom BuildKit frontends as a temporary measure. Patch status is confirmed fixed in 0.28.1.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-23T18:30:14.124Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69c5da053c064ed76f01c442
Added to database: 03/27/2026, 01:14:45 UTC
Last enriched: 06/19/2026, 19:29:02 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 199
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